A7 high beam staying on, driver side light

[Marcus25]

Hi all I've put in osram d3s lights in and the driver side seems to stay on beam or it's alot brighter and only the left light flashes. Can anyone help with what I need to do. Thanks in advance 

[Stevey Y]

Hi sounds like a dodgy ballast unit on the left light.

Steve.

[Marcus25]

17 hours ago, Stevey Y said:

Hi sounds like a dodgy ballast unit on the left light.

Steve.

Hi Steve thanks for the reply its the right light that seems to stay in as they are both brand new bulbs and it done the same with the bulbs I replaced 🤔

[Stevey Y]

6 hours ago, Marcus25 said:

Hi Steve thanks for the reply its the right light that seems to stay in as they are both brand new bulbs and it done the same with the bulbs I replaced 🤔

Hi the left hand is definitely the ballast unit if it was doing it before the way to test the right hand beam is to sit in the car and see if the right gets brighter if you put it on main beam, if not the shutter system in the unit is stuck/defective, these headlights work on the following system, low beam is when the little electrically operated shutter is in the up position, main beam command drops the shutter so you get the full light from the bulb/reflector, the flickering is because the ballast unit that feeds the bulb is on its way out, HID bulbs require a steady high voltage this causes the element to electrically heat the salt crystals in the element these develop luminosity and give you the bright light via the reflector with none of the heat involved in a Halogen gas driven bulb.

My neighbour spent over £300 on genuine Volvo HID bulbs before he asked the question and I got him another ballast unit £60 and he went and bought another Volvo bulb, problem solved, a bad ballast will eventually terminate your new bulb, the ballast unit is either behind the bulb cover, underneath the light unit or mounted on the side of the light unit its a large square thing encased in alloy.